An investigation is under way into allegations that the passport details of thousands of football fans were sold on the black market by an official linked to Fifa.

The Information Commissioner's Office, which regulates the Data Protection Act, confirmed it has launched an inquiry into claims that the details of 35,689 English fans who attended the World Cup in Germany in 2006 may have been sold unlawfully for profit. Preliminary investigations by the authority suggest that the details of 7,200 England fans have been traded illegally.

Mick Gorrill, head of enforcement at the ICO, said the investigation was prompted by claims in a Norwegian newspaper last month that the details of 250,000 fans who watched games at the 2006 tournament had been sold to ticket touts ahead of this summer's tournament in South Africa.

Gorrill said: "We have contacted Fifa regarding the allegations and will be liaising with the organisation further as we move forward with an investigation. Our initial enquiries suggest that the number of individuals affected is approximately 7,200.

The authority is looking at claims that a "rogue employee" of Match Hospitality, Fifa's official ticketing agency, may have sold the information to black market touts who could then get in touch with individuals and offer to buy their tickets before they, in turn, illegally traded the same tickets at big mark-ups.

The Norwegian newspaper Dagbladet reported it had gained possession of the list of 250,000 records, and said it had obtained several emails in which a Match employee offers the lists for sale to a major player on the black market. The newspaper claimed it has confirmed the seller's identity.

Jaime Byrom, chairman of Match Event Services and Match Hospitality's biggest shareholder, the Manchester-based Byrom plc, has told Dagbladet that it was not aware that the information had been sold and that it had taken every possible step to prevent the unauthorised sale of tickets. It is understood that an employee may have obtained the confidential lists without the knowledge of the firm.

The full list includes the personal details of a number of high-profile fans, including those of the former Swedish prime minister Ingvar Carlsson.

Match Hospitality, owned in part by a media company run by Philippe Blatter, nephew of the Fifa president, Sepp Blatter, won exclusive rights to sell ticket hospitality packages at the 2010 and 2014 tournaments three years ago. The firm was criticised for over-pricing packages for this summer's World Cup, resulting in empty seats at most matches in South Africa.